Construction for rotary pumps



March 16, 1954 H. HARVEY 2,672,100 CONSTRUCTION FOR ROTARY PUMPS Filed July 1, 1949 2 Sheets-Sheet l IN V EN TOR. Hev Harv/12y March 16, 19 54 HARVEY 2,672,100

CONSTRUCTION FOR ROTARY PUMPS Filed July 1, 1949 2 Sheets-Sheet 2 f L/Q u 6b J 7 I j l g V r a i T i s u f0 4% 14ft arney I are carried in the case inward Patented Mar. 16, 1954 CONSTRUCTION FOR ROTARY PUMPS Herbert Harvey, Los An mesne assignments, to

poration,

geles, Calif., assignor, by United States Steel Cora corporation of New Jersey Application July 1, 1949, Serial No. 102,570

2 Claims.

This invention has to do with a construction for rotary pumps such, for example, as gear pumps, or the like, and it is a general object of the invention to provide a pump construction which involves adequate, dependable bearings carrying the rotating parts and which provides practical, effective and dependable fluid seals for the rotating parts, which seals will operat over a long period of time without attention or ap preciable variation in action.

Rotary pumps such as gear pumps used to handle various fluids commonly give trouble by reason of the fluid being pumped leaking around or along the shafts that carry the rotating parts and ordinary packing means employed in such structures may operate for a limited time under ideal conditions, but usually wear rapidly, and if the fluid being handled carries foreign matter such packing constructions erode and, as a result, the performance of the pump is not uniform. I

A further object of the present invention is to provide a rotary pump wherein the shafts carrying the rotating parts are supported in the case by anti-friction bearings while sealing sleeves of the bearings and effectively prevent any appreciable leakage of fluid along th shafts. With the construction of the present invention the sealing sleeves which fit around the shafts are not relied upon to establish or to maintain an absolute fluid-tight connection around the shafts, but rather, theyare of substantial length and they fit the shafts with some clearance, to the end that flow around or along the shafts is elfectively restricted so that there is but limited leakage and the fluid that does leak is conducted back into the body of fluid being handled by the pump.

Another object of the invention is to provide a rotary pump in which lubricant seals are located inward of each of the anti-friction bearings and the lubricant seals separate the lubricant at the bearings from the fluid which is passed by the fluid seals.

A further object of the invention is to provide a rotary pump wherein the case that handles and carries the various working parts is sectional.

The various objects and features of my invention will be fully understood from the following detailed description of a typical preferred form and application of the invention, throughout which description reference is made to the accompanying drawings, in which: Fig. 1 is a vertical longitudinal sectional view of the pump provided by the present invention. Fig. 2 is a plan section of the pump taken as indicated by line 2-2 on Fig. 1. Fig. 3 is a vertical transverse sectional view of the pump taken as indicated by line 33 on Fig. 1. Fig. 4 is a vertical transverse sectional view taken as indicated by line 4-4 on Fig. 1. Fig. 5 is an enlarged detailed sectional view taken at one of the anti-friction bearings showing the lubricant seals related to that bearing, and Fig. 6 is an enlarged detailed sectional view taken in the direction of line 66 on Fig. 3, indicating the manner in which a limited amount of fluid may circulate in or through the fluid seals as the pump operates.

The construction provided by the present invention is applicable, generally, to rotary pumps and is particularly practical as applied to gear type pumps, or the like. In the case illustrated the invention is shown applied to a gear type pump wherein two simple or conventional gears are meshed and serve as the members which propel the fluid, and the construction is such as to develop a substantial pressure.

The construction embodying the present invention comprises, generally, a case A which defines chambers l0 through which fluid is circulated by meshing gears B. Spaced shafts C and D carry the meshing gears B and-are rotatably supported in the case by means of anti-friction bearings E. Lubricant sealing means F i provided'in connection with each bearing E and fluid sealing means G is provided on each shaft inward of each of the anti-friction porting the shaft.

The case A, in accordance with the present invention is of sectional construction and includes a main or center section l2 having flat ends [3, end plates M which are secured to the sides l3 of the center section l2, bearing plates l5 which are secured to the outer sides of the end plates l4, and cover plates l6 which are secured to the outer ends of the bearing plates IS.

The main or center section H! of the case is a block-like element with openings extending through it from one side 13 to the other,'which openings form the chambers l0 and communicate with or join each other. The walls I! of the openings through the case which define the chambers [0 are curved concentric with the axes of the shafts C and D, as clearly illustrated in Fig. 3 of the drawings. Liquid handling ports is and 20 enter the block forming the center bearings supsection I 2 from diametrically opposite points and open "into the chambersl0 where the" chambers clubricant seal F,is located ,imr ediately -inward iota-each,

adjoin at the center of the block. One of these ports acts as an inlet port while the other acts as an outlet port and, as is characteristic of gear pumps when the gears are operated in one direction, one of the ports is the inlet port, whereas when the gears are operated in the opposite direction the other port is the inlet port.

The end-plates H may be simple fiat plates which are alike and which are secured to the ends E3 of the center section 12 by suitable fastening means such as screw fasteners 22. The particular fasteners shown in the drawings are bolts suitably spaced around the case. In the construction illustrated each end plate 12 pm.

vided with an outwardly projecting central boss 1 23 so that the portions of the plate which pass the shafts and which carry the b arin ,12 are of substantial thickness or extent lengthwise of the shafts, as clearly shown in Fig. 1 .of $118 drawings. The end plates [4 have round openings or bores :2 5 concentric with {the shafts and D, which openings contain the fipid seals as will be hereinafter described.

The bearing plates i5 are preferably like plates secured to the-outer sides ols iifi o the bosses 23 on the end plates M. In cease-itinetrated the bearing plates {1136:S8Cl1fi6d 3130 the end plates M y suitable fast n rs I shown in he p s rews enga ed-inflame. open n s 28 provided'inth rbe sesrfi- The bearin plate ii-,5 have a oun pe in s 91 whores which alien with, the openings ;i he .end plates and which contain the anti-f ct n hearinss 1E- The cover plates A36 arezsecured to the center ends or faces SI of the bearing slates preferabl'y zby he- -:s m irfsast ner :2 49th. h'b l .e e rin pl t :t 'the s n plat s. "In the .form of construction illustrated gthe shafts end 2D aresupported so Ethat Ztheyar-eip h llel with each other on spaced: xesrthatiextendctlrough ,;the chambers "IYOIiIlBiihB'gSBCfiQXI J, 2,. The shaft 13 eter- :minates :in --;the .case "With its ycnds within :athe bearin mlatesiandso tha zit is confine; in the case by the cover platesztfi. iZ-EheishaftgC seconfi-ned rat one end of :the ;:case .by :the 7 cover plate occurring ,atxthat end :of :the case, whereas Tan extensionifi of the sha-ft-ic gextendsdnomethe other end thereof to project outwardly through iamoperring: :3 6; provided in the zotheracoverzplate. in 3 practice, a suitable lubricant sseal 3:1 315131311)- vided around :the :shaft -:,extens1ion 3,5 avhereait passes rcthrough sthe 1;last mentioned caver :-plate.

':The :fluirl "circulating imgenibers 'iiB which :are preferably;-gearseareafixed :oreheyedonthe shafts C and D- within the chambers 3113,, andzinrthe mesh in the center of-"thecase where the. :chamberslfl join.

The bearing-s {E --are-pr eferably .antiwfricticn bearings supportedin :the bearing pla tes t5 and serving to rotatably support theend portions of the shafts- 0 and 4D. -.'In -the 2 case- {illustrated each antifriction-: bearing :is; carr-i inzan onensn e .1

to retain: the ,rollers in; proper acsitirpr Y r elati .the... rings 40.

em. aceordanceewith- :the ;-present invention ;a

:5 case illustrated 1 they are simple spur-gears -that 5 4 ranged or faced as to effectively confine lubricant to the bearings. As best shown in Figure 5, each lubricant seal F includes a holder 45 mounted in the bearing plate and a sealing member 46 car ried by the holder with a sealing lip in engagement with the shaft. A suitable retainer or actuating member 41 engages the lip portion of the sealing member to hold it in prpper sealing engagement with the shaft. The 1115 'faces outward or toward the bearing so that it is highly .efiective in checking the escape of lubricant inward along the Shaft from the bearing.

The present invention provides fluid sealing means .Q around shafts C and D inward of the shaft supporting bearings E and in the prefer-red arrangement the fluid sealing means are confined to and carried by the ends of end plates 14 of the'cas'e between the gears that are secured on the shafts and the lubricant seals F which are provided on the shaft inward of the bearings E.

;In the preferred fori'ii ,of the .inyention each fluid sealingmeans s a ,simpleitubular iriefnber or sleeve .3d I hfi rtssmi'gly ir'ito'an opening 25 inla n end ipla e M while fits. around shaft w th ed abl tw i i a lj arisin ou the r sent 'in ee iqn th s a ts m y b minengerin is e ce ts-e m a t co t uction 3 sall reame- F Q ve tn. slee es e are n s e-s a h rings even though, in practice they,rn ,lqadvanta fifi fi ifrm l 'fi 1???- Me materi $35 as bronze, or thelike.

1 the fiQ c he nvsnt en li s ra ed th fluid sealings e e sna ierr deit i ih i jnne ends wi i rou wamyradial rn siee ns flan s i18 l ca e w h h membe s .111 a de ined th central s c 4. e -the t ase and the fac s 1 o t e flan e define th -endsofihe cha e -i wh ch th s at .23 o erate {Sh f an e ti m t e-skewers a ains outwa d dis lacement and, in practice they may be formed of b onz o o h suitab hearmsmaterialiso t a he vpri /id -sei t a. e e a es at th ends of t g ar anda le ely fit in he .en stef x he se r s tha th r 1 21 appr iable-l aka e e c-this. p n

.n he hm operates, eth rsh ft-s turn in t fi iins sle ves 5 85 with working clearance orig- 'inally established{between :these parts v or which 250cm, occurs,,as a result of wear. As pressure is developed on fluid being handled my .the ,pump through {the action of :the gears :on the shaft, it

::tends to leak or :escape. along. :the, shaftsrtoward and inmracticeia very, small amount .of fluid -actuallyrfiows athrqugh thesleeves. since the 513151655 hare; ngtrelied iupon as jgbearings r and do not act as bearings, thezilimifiti =:larance proid abeiw e -the c leeve film-3th? shafts will :mma n .e bs ae nsiant were ve l n ,period of time solthat, particular pump constructed in accordance with the invention, will have a given arno int chicakage and-this leakage u smei e seb ieei e l i e tarit a t r t sewer epe et ',nee-W hi emtesemmye iiic t r Inh r t-betwee e c sleeve and;its, adjoin' g lub nt seal Fand lmlaeated steache d of the structure are joined by a connecting passage H. Extensions 12 of each catch chamber communicate with return ports 13 which are provided in the end plates 14 and which extend inwardly to communicate with the ports which handle fluid being circulated by the pump. In the preferred form of the invention the passages 1| and 12 of the catch chambers are in the form of channels or recesses provided in the inner sides of the bearing plates 15 as shown in Fig. 4 of the drawings. In accordance with the present invention there are two return ports 73 in each end portion of the case or in each end M of the case, so that each catch chamber may communicate with each such return port. In practice the two return ports in each end I 4 extend to and communicate with the ports l9 and 29, one of which latter ports is an inlet port while the other acts as a discharge port. Closures or plugs 86 are provided in the return ports 13 which communicate with the discharge port, with the result that fluid passed by the sleeves 60 and entering the catch chambers is conducted from the catch chambers to the inlet port in the main section of the case. It will be apparent that when the direction of operation of the pump is reversed the plugging of the return ports 13 may be reversed so that under any operating condition fluid escaping past the fluid sealing sleeves 60 is conducted to the inlet side of the pump.

From the foregoing description it will be apparent that the general construction of the case provided by the present invention is simple and inexpensive while at the same time the shafts which carry the gears are effectively supported in antifriction bearings so that they will operate efliciently over long periods of time. The lubricant applied to the bearings, as through suitable lubricant connections 85, is efiectively maintained in or at the bearings and the slight or limited leakage that occurs around the shafts past the sealing sleeves 60 does not escape from the exterior of the case and does not ever reach the bearings, but rather is sim ly circulated through the catch chambers and the return ports to the inlet or suction side of the pump. With proper limited working clearance between the sleeve 60 and the shafts a limited amount of leakage occurs around the shafts and consequently this leakage does not materially impair the action of the pump.

Having described and application of only a typical preferred form my invention, I do not wish to be limited or restricted to the specific details herein set forth, but wish to reserve to myself any variations or modifications that may appear to those skilled in the art and fall within the scope of the following claims.

Having described my invention, I claim:

1. A rotary pump comprising a case of sectional construction having a main central section, apertured end plates fixed to the sides of said central section, apertured bearing plates fixed to the sides of said end plates, and covers fixed to the outsides of said bearing plates, said central section having a pair of connecting chambers formed within its interior and an inlet and an outlet communicating with said chambers, opposed pairs of axially aligned bearings supported in said bearing plates and spaced from the opposite sides of each of said chambers, a pair of shafts, each of which is rotatably mounted in a diiierent opposed pair of said bearings and extends through a different one of said chamber fluid circulating elements carried by said shafts within said chambers, and means in the space at each side of each chamber for excluding fluid in the chamber from the adjacent bearing, each of said means including a sleeve snugly supported in one of said end plates adjacent the chamber and rotatably receiving the shaft, and a seal supported in the adjacent bearing plate adjacent the hearing inwardly thereof and spaced from the outer end of said sleeve and rotatably receiving the shaft, the intervening space between said sleeve and said seal constituting a catch chamber for fluid which leaks between the shaft and seal, said end plates containing return passages from said catch chambers to said inlet.

2. A'rotary pump comprising a case having a pair of connecting chambers formed within its interior and an inlet and an outlet communicating with said chambers, opposed pairs of axially aligned bearings supported in said case and spaced from the opposite sides of each of said chambers, a pair of shafts, each of which is rotatably mounted in a different opposed pair of said bearings and extends through a different one of said chambers, fluid circulating elements carried by said shafts within said chambers, and means in the space at each side of each chamber for excluding fluid in the chamber from the adjacent bearing, each of said means including a sleeve snugly supported in the case adjacent the chamber and rotatably receiving the shaft, an annular metal holder mounted in the case adjacent the bearing inwardly thereof and spaced from the outer end of the adjacent sleeve, a flexible sealing member mounted in said holder and having a lip rotatably receiving the shaft at a location spaced from said sleeve, and a retainer between said lip and said holder maintaining the lip against the shaft, the intervening space between said sleeve and said lip constituting a catch chamber for fluid which leaks between the shaft and sleeve, said case having return passages from the catch chambers to said inlet.

HARVEY.

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